Numerous treatment options are known in the art for patients that are diagnosed with a condition that precedes prostate cancer. Most commonly, watchful waiting is preferred over open or transurethral surgery, or drug treatment. However, all of those options have various disadvantages and often fail to arrest progression of the condition to prostate cancer, or where progression is temporarily halted (e.g., using finasteride), prostate cancer tends to occur with some delay at a significantly higher grade. Still further, most known treatment methods are also largely ineffective in alleviating symptoms associated with BPH.
For example, WO 2005/092342 teaches a combination of a tailored alpha-1 adrenoceptor antagonist, which is selective for an alpha-1a over alpha-1b receptor subtype (but non-selective for alpha-1a over alpha-1d receptor subtype) with a muscarinic receptor antagonist and a further optional a 5-alpha-reductase inhibitor. Similarly, U.S. Pat. No. 6,200,573 teaches combinations of an alpha-1 adrenoceptor antagonist with a phytotherapeutic agent (e.g., Serenoa repens extract) for treatment of LUTS and BPH. Alpha-1 adrenoceptor antagonists are often relatively effective in reducing at least some of the symptoms associated with BPH, however, often produce various undesirable side effects due to their binding with other adrenoreceptor subtypes.
In other known examples, lonidamine and analogs thereof were reported as therapeutic agents for treatment and prophylaxis of BPH as disclosed in WO 2006/015283. However, such compounds typically inhibit cellular energy metabolism and affect testicular steroid hormone production and are thus not well tolerated over a prolonged period of time. To avoid at least some of the problems associated with lonidamine and related compounds, tadalafil and other inhibitors of type-5 phosphodiesterases can be used to treat the symptoms of BPH and LUTS as described in WO 2007/047282. While such inhibitors have a relatively favorable safety profile, comparably high cost of such compounds may preclude widespread use.
In still further known methods of treating BPH and other emiction disorders, numerous combinations of plant extracts (e.g., from ginseng, gingko, cassia twig, cinnamon, liquorices, etc.) were proposed, as for example, in U.S. Pat. App. No. 2005/0220904. Here, raw materials are decocted or extracted in an ethanol solution or water, and subsequently concentrated and dried for preparation of a therapeutic composition. Other known methods include use of a lignan preparation in combination with a second plant extract (e.g., isoflavone, tocopherol, phytosterol, polyphenol, catechin, or anthocyanin) to produce a composition that delays onset of prostate cancer as described in U.S. Pat. App. No. 2006/0234948. Furthermore, green tea has been reported in several models to accumulate in prostate tissue and to possibly prevent cancer (see e.g., J Nutr. 2006 July; 136(7):1839-43). Unfortunately, successful use of herbal remedies for treatment of prostate cancer has proven elusive, which was reiterated in the guide for making treatment decisions of the American Cancer Society (“While the results of lab studies have been promising, at this time the consensus of available scientific evidence does not support claims that green tea can help prevent or treat any specific type of cancer in humans”).
Thus, while numerous compositions and methods of treating symptoms associated with HG-PIN and BPH are known in the art, almost all of them suffer from several disadvantages. Therefore, there is still a need for improved compositions and methods of treating symptoms associated with HG-PIN and BPH.